The present invention relates to a gas seal between a rotating body and a plane to which the body must be kept airtight in a rotary engine or in a compressor.
It is vitally important for the sake of maintaining machine efficiency to prevent gas leakage between a rotating body and a plane to which the body must be kept airtight in a rotary engine or in a compressor.
The rotating body and a plane to which the body has to be kept airtight differ depending on the type of the rotary engine. In an engine of the type having a circular rotor rotatably housed within the housing and wherein a pair of the inside surface of the housing protrudes toward the rotor to slide against the rotor, the rotating body is the rotor and the plane to be kept airtight is the rotor-sliding part of the housing.
Moreover, in an engine of the type having a rotor rotatably housed within the housing, a recess on the inside surface of the housing, a circular rotary seal rotatably provided in the recess, and a projection out from the recess in the rotary seal which slides against the rotor, the rotating body is the rotary seal and the plane to be kept airtight is the rotary seal-contacting part of the recess in the housing or the rotary seal-contacting part of the rotor.
The conventional method of keeping such parts airtight includes providing an apex seal on the housing side instead of on the rotor side and pressing the apex seal against the rotor with gas pressure to thereby maintain airtightness between the rotor and the housing.
For structural reasons of the rotary engine or the compressor, however, it sometimes happens that the sealing means must be provided on the rotor side, and in that case the specific structure of the sealing means is important together with the location of that means on the rotor surface and the airtightness between the two longitudinal ends of that means and the housing. Especially when the sealing means is elongated in the radial direction of the rotor, the airtightness between the longitudinal ends of that means and the housing presents a serious problem.